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By Lippe D. Sadwin

A high-speed streak camera method for making equation of state measurements (shock and particle velocities) on samples of rock under dynamic load conditions is described. Experimental data are given for tests on 12 samples representing 5 rock types. Analysis of these data shows that the method is practical and that good reproducibility of results can be obtained. The pressure range covered in the tests was from 1 to 50 kilobars.

Jan 1, 1966

By G. S. Scott, G. W. Jones, F. E. Scott

An important activity of the Bureau of Mines is the promotion of safety in mining and industry . In connection with these activities , the Bureau determines the explosion hazards of combustible gases , liquids , and solids , and investigates means by which explosions may be eliminated or reduced in violence . The limits of inflammability and ignition temperatures of combustible gases , vapors , and solids are of practical importance because such materials can be manufactured , transported , and used with greater safety , provided the range of concentrations and temperatures that cause explosions are known. Acetic anhydride , ( CH3CO) 20 , with which this report is concerned , is a liquid at ordinary temperatures . It is used in the preparation of a number of organic chemicals and in the manufacture of photographic film and of artificial silk . It is perhaps the most important acetylating agent for industrial uses - a property that is especially important at this time because of its direct application in the manufacture of munitions . The sample tested was supplied by the Carbide & Carbon Chemicals Corporation . Its specific gravity was given as 1.083 at 20/20 . The vapor pressures , supplied by the manufacturer , are plotted in figure 1 .

Dec 1, 1943

By E. D. Regad, W. E. Wallace, V. Vallythan, V. Castranova, P. Hathaway, F. H. Y. Green, M. J. Keane

"Abstract—Inhaled particle contact with pulmonary surfactant in the hypophase lining pulmonary alveoli was modelled in vitro by exposing two respirable sized dusts, kaolin and silica quartz, to lecithin, a major component of pulmonary surfactant, emulsified in physiological saline. Lecithin adsorbs to the dusts upon incubation at 3TC and suppresses their cytotoxicity as measured by pulmonary macrophage and erythrocyte assays, suggesting that pulmonary surfactant provides a defence system against prompt cell membrane lysis by inhaled dusts. Subsequent pulmonary macrophage phagocytosis and lysosomal enzyme digestion of the coated dusts was modelled in vitro by incubation with phospholipase A2 for one hour. With increasing lipase activity, silica haemolytic potential was restored to native silica levels. Kaolin was retoxified to levels far in excess of native kaolin haemolytic potential. Elution, thin layer chromatography and phosphate assay of treated dusts indicate that most lecithin on silica is digested to lysolecithin and desorbed, silica retoxification being due to surface and adherent lysolecithin effects. Most lecithin on kaolin is not digested in the same time; that which is. results in adherent lysolecithin which is responsible for the kaolin retoxification. Digestion with phospholipases A2 and C together produces only weakly retoxified kaolin. Results suggest that surface adsorption properties which control the adherence of prophylactic surfactant distinguish the pathogenic potentials of quartz, kaolin and mixed dust.INTRODUCTIONERYTHROCYTE HAEMOLYSIS and pulmonary macrophage enzyme release assays show quantitatively comparable high cytotoxicities for both silica quartz and kaolin respirable sized dusts (BROWN, et al., 1980; DANIEL and LE BOUFFANT, 1980.) This contrasts with the strong potential for respirable quartz dust to induce pulmonary fibrosis and the much more limited potential of kaolin dust to do the same (MORGAN and SEATON, 1975).In an attempt to understand this anomalous situation, assays were performed on quartz and kaolin dusts incubated with dipalmitoyl lecithin emulsified in physiological saline, to simulate the initial contact of a respired dust with the pulmonary alveolar hypophase. The ability of kaolin dust to adsorb dipalmitoyl lecithin from physiological saline has been quantified (WALLACE, et al., 1975). Such lecithin treatment suppresses the cytotoxicity of both silica and kaolin to background levels (WALLACE, et a1.,1984).Surfactant coated detoxified dusts should then be phagocytised by pulmonary macrophages, incorporated into a macrophage secondary lysosome and exposed to hydrolytic lysosomal enzymes. Among these is phospholipase A2, which hydrolyses diacyl lecithin to lysolecithin. This was modelled by incubating lecithin treated dusts with phospholipase A2 in vitro to determine if the enzyme can digest the dust-adsorbed lecithin, and if the retoxification differs between the two dusts in a manner which might distinguish their pathogenicity."

Jan 1, 1988

By Thomas E. Marshall, Patrick A. Kinek, Gerald L. Finfinger

The purpose of this investigation was to evaluate the integrity of the existing shutoff valves and actuators used under high-temperature conditions in the Bureau of Mines' horizontal borehole methane drainage pipe- line system and to determine the potential for improvement in the system. In the field tests, both fire-safe ball valves and standard brass ball valves were initially subjected to a 30-min pan fire without thermal protection. Neither valve could maintain line pressure beyond 11 min in a fire that reached temperatures between 500° and 700° C. Based on the test results, it was concluded that the brass ball valve used in the Bureau's methane drainage pipeline system can be retrofitted with an inexpensive "fire bag" to substantially increase its integrity under mine fire conditions.

Jan 1, 1986

By T. Christos

The explosive oils, nitroglycerin (NG) and ethylene glycol dinitrate (EGDN), were extracted from dynamites by a halocarbon solvent and were then determined by high-pressure liquid chromatography. Separation was achieved by liquid-liquid chromatography on a column packed with Durapak-Carbowax 400/Corasil II and the eluted NG and EGDN were detected with a double-beam ultraviolet detector.

Jan 1, 1973

By D. D. Bolstad

This report describes the construction and use of a direct-reading azimuth protractor (DRAP) by the Bureau of Mines for measuring fracture orientations in mines, tunnels, or other excavations having a magnetic environment. The DRAP allows a rapid and simultaneous measurement of dip and azimuth of dip of a fracture plane. The instrument is rugged, lightweight, and easily constructible from standard hardware items. The DRAP can measure dip to within ±0.5° and azimuth of dip to within ±5° of corresponding values obtained with a Brunton compass.

Jan 1, 1974

By V. A. Marple, K. L. Rubow

"IntroductionA particle dispersion system has been developed to aerosolize bulk powders or material deposited on surfaces such as filters. The size distribution of the aerosolized particles can then be obtained by sampling the particles with an aerosol sizing instrument such as a TSI aerodynamic particle sizer (APS) or a cascade impactor.Of particular interest is the applicability of using this technique to obtain the size distribution of particles collected on filters. This system has been used to determine the size distribution of coal dust particle collected on membrane filters. The use of this device in this application is quite intriguing in that, if this technique can be shown to accurately determine the size distribution of airborne particles, one can easily collect particle samples using either personal or area particle samplers, determine the mass concentration of the collected material through gravimetric techniques and then use the particle dispersion system coupled with the APS to determine the particle size distribution. With this technique one can determine the particle size of dust in environments, such as underground mines, where it would be inconvenient or impossible to use a particle sizing instrument.Particle Dispersion SystemA prototype particle dispersion system has been developed for aerosolizing particles. A schematic diagram of the system is shown in Figure 1. The system consists of mechanism for advancing the particle sample beneath a dust pickup tube, a venturi for deagglomerating the particles, and a instrument for analyzing the aerosolized particulate matter.The procedure to analyze a particle sample is as follows. The particles to be aerosolized are placed on a sample plate from where the particles are picked up by an air stream flowing upward in a small capillary tube (dust pickup tube). This tube operates as a small vacuum cleaner passing over the sample plate. The air is drawn up the capillary tube at a rate of 2 L/m by a venturi aspirator. This is accomplished by placing the outlet of the capillary tube near the throat of the venturi. The accelerated velocity of the air creates a low pressure in this region which draws flow up the capillary tube. From the outlet of the capillary tube particles are transported to the inlet of the APS where a small fraction are sampled and the aerodynamic diameter of the particles determined. The particles which are not measured by the APS are passed into a HEPA filter."

Mar 1, 1989

By Kenneth L. Rubow, Virgil A. Marple

"INTRODUCTION Respirable dust is defined as the dust which penetrates to the alveolated regions of the lungs. Due to the size selective nature of the particle removal mechanisms in the nasal passages and lung airways, criteria defining respirable particles must be a function of the particle size. Three criteria defining respirable particle penetration are shown in Figure 1. These criteria have been defined by the British Medical Research Council (BMRC), the American Conference of Governmental Industrial Hygienists (ACGIH) and German TBF 50-11 (1).The quantity of respirable particles in an aerosol can be measured by use of two-stage samplers. The first stage consists of a particle preclassifier with penetration characteristics corresponding to one of the respirable penetration curves in Figure 1. The large nonrespirable dust particles are removed from the airstream in the preclassifier and the smaller respirable dust particles pass on to some device which can measure their concentration (the respirable dust concentration).Instrumentation for the measurement of respirable coal mine dust has been limited by the severe conditions existing within the coal mine. The conditions of particular importance are the methane atmosphere, high humidity, and the general non-laboratory type environment. The most severe of these conditions is the methane atmosphere since any electronic or electric powered instrumentation must be intrinsically safe to operate in such an atmosphere.In spite of the difficulty of sampling respirable dust within the mines, many instruments have been developed for in mine use. Although these instruments operate under a variety of principles they generally fall within two categories: personal samplers and area samplers.A personal sampler is worn by the mines while he is performing his duties in the mine. These devices are generally small, light weight and require little power so as not to interfere with the miner's ability to work."

Jan 1, 1988

By Kenneth E. Hjelmstad

The U.S. Bureau of Mines (USBM) has developed an electromagnetic (EM) fire warning alarm sys-tem for underground mines. The system generates a magnetic field for through-the-earth signal trans-mission to microreceivers carried by individual miners. EM fields can induce electric currents in metallic conductors; if an EM transmitting antenna and an electric blasting cap array are too close, the field could induce a current in the blasting array and cause an unintentional initiation of the electric detonators. The USBM conducted tests that define the safe and unsafe regions for using electric detonators near the transmitting antenna of the warning alarm system. The minimum safe distance between a transmitting antenna and a blasting array is the distance where the induced electrical current in the blasting array is 50 mA, which is the safe current level specified in Federal mine safety regulations. Tests indicate that at transmitting power levels of 100-and 1,000-W, separation distances of 9 and 21 m, respectively, were required. These distances are small compared with the dimensions of a mine. Thus, the tests indicate that, with proper placement of the transmitting antenna, the warning system can be used safely in the proximity of blasting arrays.

Jan 1, 2010

By Nicholas Kyriazi

It is of interest to know how to obtain as high an absorption efficiency as possible from a CO2-absorption canister used in closed-circuit breathing apparatus. In this study the Bureau of Mines found that varying the bed depth and the cross-sectional area of a canister changes its absorption characteristics. In tests using four ,1 rectangular, variable-depth canisters with different cross-sectional areas, the Bureau found that, given a constant weight of the chemical absorbent, LiOH, and a constant COa input, the canisters with a greater cross-sectional area reached C02 levels of 0.5 volume-percent in the effluent gas sooner than did the canisters with a greater bed depth. However, resistance to flow through the canister increases with bed depth, and a trade-off is inevitable. It was anticipated that the efficiency of a canister would increase with increasing intergranular air space approaching the tidal volume of the breathing waveform and then level off at some point under 100 percent. This postulation was partially substantiated. Cylindrical and radial canisters were also tested and compared. It appears that shape is not as important a factor in absorption efficiency as bed depth, since neither canister differed significantly from the rectangular canisters with regard to absorption efficiency values.

Jan 1, 1980

By T. J. Ballard

The Track Rock corundum mine was among the numerous corundum deposits investigated during the war by the Bureau of Mines in an effort to develop domestic reserves of that critical mineral. In the investigation of this property 562 feet of trenches were excavated and a l25-foot adit was reopened for the purpose of locating veins to of corundum which had been previously reported to occur in that locality. Only very minor amounts of corundum were disclosed in both the surface workings and the adit. The project was begun in May 1943 and completed in November 1943.

Jan 1, 1948

By W. H. Ode, W. A. Selvig

In 1938 , the Bureau of Mines cooperated with Subcommittee XV on Plasticity and Swelling of Coal ( C. C. Russell , chairman ) , of Committee D-5 on Coal and Coke , A.S.T.M. , by testing various methods for determining expansion and plastic properties of a series of coals of widely different coking properties . One of the tests made by the Bureau was the British Standard Method for the Crucible Swelling Test for Coal.5/ Briefly , this swelling test consists in heating 1 gram of pulverized coal in a silica crucible over a gas flame under prescribed conditions to form a coke button which is compared in size and shape with a series of standard profiles numbered 1 to 9. These profiles are intended to cover the size and shape of buttons obtained from coals covering a wide range in plastic properties .. The number of the standard profile with which the maximum cross -sectional area of the button most nearly corresponds is recorded as the swelling index . Although the swelling test showed poor relationships with the various tests that were used for measuring expansion or contraction of coal during carbonization , it gave indications of having value in measuring free - swelling and caking properties of coals when burned on fuel beds . An opportunity to investigate this occurred when an engineer of an eastern public utility 'company reported pronounced differences in burning characteristics on grates of various shipments of Pocahontas coal . Some of these coals gave trouble by swelling 'excessively and clogging the grates . Samples were ob- · tained , and it was found that the troublesome coals gave decidedly higher free -swelling numbers than did the coals that performed satisfactorily . Also , it was found that the free - swelling index test gave better differentiation between coals than could be obtained from the coke buttons from the · ´`standard volatile -matter test or from agglutinating - value results . The results of the free - swelling tests were considered by the Subcommittee on Plasticity and Swelling , and a special group of the subcommittee , under the chairmanship of R. A. Sherman , was delegated to study the test method . Ostborg , Limbacher , and Sherman , ofthe Battelle Memorial Institute , ' investigated the various factors affecting the test and found that the swelling index was a good indication of the suitability of coal for performance on residential -type stokers from the standpoint of the coking characteristics of the coal . Data were presented also showing that the indexes wer helpful in the selection of coal for industrial underfeed stokers .

Oct 1, 1946

By Todd M. Ruff

The lack of visibility near earthmoving equipment resulted in six fatalities in U.S. surface mining operations during 2003. These accidents were the result of either a piece of equipment striking another vehicle or worker, or the equipment traveling over the edge of an embankment. Figure 1 is an example of a recent accident that resulted in serious injuries to one worker and fatal injuries to two others when a van parked in front of a haul truck. Two fatalities occurred in separate incidents when front-end loaders struck workers. Another two workers were killed when their equipment backed over the edge of a highwall or dump point [1]. There is clearly a need to provide better information to equipment operators regarding their surroundings. [ ] Researchers at the National Institute for Occupational Safety and Health (NIOSH), Spokane Research Laboratory, are working to reduce these accidents by developing systems that sense obstacles and changes in terrain near the equipment and provide this information to the operator. Many off-the-shelf proximity warning systems that were developed for automobiles, light trucks, and recreational vehicles were evaluated on off-highway dump trucks [2]. Many limitations were found with existing systems, including frequent false alarms, limited detection range, a lack of specific information on an obstacle (e.g., location, identity), difficulties in finding suitable mounting locations, and an inability to withstand the environment. These limitations have necessitated the development of new systems designed specifically for large, off-highway, earthmoving equipment. New off-the-shelf systems available for mining equipment include radar and tag-based detection systems. Prototype systems now being developed include a proximity warning system based on the Global Positioning System (GPS) and a computer-assisted stereovision system. Development of these new systems was accomplished by working with manufacturers to modify existing systems to meet the needs of surface mining and through cooperative research with organizations to develop completely new solutions. A typical proximity warning system consists of a sensor or antenna mounted on the equipment that detects the presence of obstacles and an alarm interface in the cab of the equipment. Some systems, as described in more detail below, also require that other vehicles and personnel on the ground be outfitted with electronic tags that transmit an “I’m here” signal back to the system (e.g., radio signal detection systems or GPS). Many types of proximity warning systems are on the market, but they are not all discussed in this paper. APPROACH In past work, engineers at NIOSH evaluated several off-the-shelf proximity warning technologies in order to verify their effectiveness on off-highway dump trucks [2]. Dump trucks were chosen because of the number and severity of accidents involving this type of equipment and because extensive blind areas around these trucks are typical. This experience allowed engineers to limit the number of systems chosen for long-term tests at mine sites to those systems showing

By E. D. Gardner

"The Bureau of Mines receives many inquiries concerning favorable areas in which to prospect for gold, procedure to be followed, equipment required, and allied subjects. This circular has been prepared for use in reply to these inquiries.Interest in gold mining and prospecting for gold remains steady. From time to time many people take to the field to search for new gold deposits. A large percentage of them have had no previous experience in prospecting for lode gold; this paper has been written with the hope that it might assist these newcomers.A majority of the metal mines in the United States have been discovered by qualified prospectors who were searching for valuable minerals at the time. Chance, however, always has played a large part in finding mineral deposits. Some of the discoveries of the past were made by men on other errands, such as rounding up burros or hunting game. Accidental discoveries of ore bodies have been made in building roads and trails and in excavating for mine struc¬tures. Evidence of ore has been brought to the surface by burrowing animals and by ants; gold found in the craws of fowl has led to discoveries of deposits. Important discoveries have been made by men who had no knowledge of rocks or minerals; on the other hand, many ore bodies have been found by experienced prospectors, sometimes after hundreds of untrained men had already passed over the ground.The prospector who carries on his work diligently and intelligently is of course more likely to be rewarded for his efforts than the lazy or unintelligent worker; nevertheless, it is obvious that if valuable deposits are not present at the place being prospected none will be found. Conscientious and painstaking efforts to trace gold to its source usually disclose nothing more valuable than some narrow, unworkable seams; however, many deposits that were developed into profitable mines were found by this method of prospecting. Although some prospectors have made several lucky strikes, many others have spent their working lives searching for gold without finding anything worth while. Probably only one prospector out of several thousand ever finds anything worth developing. Moreover, only 1 out of every 300 or 400 properties developed becomes a profitable mine.Prospecting was begun in the Western States in the fifties as the miners looked for the source of gold found in placers. The search for gold has been continuous since that time; the number of prospectors in the field at any one time, however, has varied greatly. Except in some desert regions, practicallyall of the placer fields now being worked were discovered by old timers; more-over, most of the important gold districts were found by early prospectors. Important discoveries of lode mines, however, have been made from time to time. Most of the area in the mining regions of the West has been searched many times by prospectors, and nearly all of the easily found deposits have been located, but it is reasonable to expect that new gold mines will continue to be found. Most of the future discoveries undoubtedly will be of deposits that do not outcrop. Prospecting for such deposits requires considerable digging.Several important discoveries were made in 1934. One of these, the Rogers-Gentry gold mine at the edge of Antelope Valley in Los Angeles County, Calif., was found by an experienced prospector on an old patented homestead a number of miles from the nearest producing mine. The initial discovery at this mine was an iron-stained, decomposed, silicous limestone outcrop, with no vein structure evident at the surface, near a small, barren quartz outcrop and a water seep. Another discovery, the Silver Queen gold mine, in the same general region and near Mojave, Calif., was found by an experienced miner on an open fraction 400 by 1,400 feet in size between two old properties that were thought to have been worked out years ago. The Silver Queen discovery was made as the result of finding a"

Feb 1, 1950

By E. J. Gleim

Many people consider the mining of coal to be an extremely hazardous occupation; but it should be remembered that most large industries have to meet special conditions which, if not dealt with properly, might become hazards to life and property. Mining men may not always be fully aware that some practices and certain equipment that is incorrectly designed or maintained can lead to dangerous conditions. In endeavoring to help the coal-mining industry to prevent accidents and disasters, the Bureau of Mines has engaged in a program of education on conditions and practices that must be avoided. An effective way to teach safety is by visual demonstration. For example, it is generally known that certain kinds of electrical flashes have ignited explosive atmospheres in mines, but actually to see and hear explosions caused by electrical sparks of different size and character under laboratory control is likely to teach a much more emphatic and lasting lesson than would be learned by merely reading about them. The interest manifested by those who witness the demonstrations seems to prove that this is true. The purpose of the demonstrations is not to discourage the use of electricity in mines, but rather to indicate what types of equipment (including some generally regarded as harmless) can ignite gas and what safeguards have been developed to prevent such ignitions. It is hoped that this information will improve the ability of mining men to cope with underground hazards.

Jan 1, 1937

By E. G. King

The work described in this Bureau of Mines report was undertaken to fill a need of industry for high-temperature heat-content data for uranium tetrafluoride. Without such data, heat balance evaluations of processes involving this substance are seriously hampered. Measurements of the heat content of uranium tetrafluoride were conducted at temperatures from 298° to 1,350° K. The melting point and heat of fusion were determined. The results are presented in suitable tabular form, and representative heat-content equations are included.

Jan 1, 1961

By J. F. Barkley

"In the course of the Government's Fuel Economy Survey of its own power plants, studies and tests have been made of various oil-burning equipments under power-plant boilers. There are now many types of burners being offered in the relatively limited field of power-plant use. The majority of the types used may be grouped into two general classes- those using steam to effect the atomizing of the oil, and those using mechanical means.Burners using steam have had the most prominence in this field for a long period. The mechanical atomizing type of burner successfully applied on shipboard, however, pointed to a possible betterment in land work. The vision presented itself of a burner that would need no steam for atomizing that would permit of air inlets or registers compactly arranged as a part of the entire burner, and that would only require the natural stack draft usually available in land boiler furnaces. Hence, rather recently there has been much development along this line, resulting in various types of burners.In Table 1 are grouped test items chosen from many tests showing representative analyses of the products of combustion obtained with various burners installed in various types of furnaces. In all these tests the burners were handled by experts and represent practically the best attainable for that particular arrangement. The boiler efficiencies ranged from 70% to 80%. It will be noted that the burners using steam for atomizing were able to secure slightly better 002 and less 02 without the presence of CO."

Feb 1, 1926

By Robert S. Sanford

The Broughton and Ring magnetite deposits in Essex County, N. Y., are thought to be in a mineralized belt that extends from the Lake Sanford mining district to Lake Champlain and passes through the Mineville district. The country rook is syenite-gneiss, similar to that in the Mineville area. The Bureau of Mines conducted a vertical magnetometer survey of the area. On the Broughton properties there are no indications, magnetically, of magnetite in any degree of concentration. 'On the ding properties a number of sharp, localized magnetic anomalies were observed. One core-drill hole was bored to a, depth of 48.3 feet, also, to test one of the strongest anomalies. The field work was in progress from December 1943 to July 1944. Although no iron ore was intersected by' the drill hole, it showed that the amphibolite rook, at a depth of 6 to 100 feet below the surface, contained enough magnetite and iron sulfides to account for the anomalies recorded by the magnetometer survey.

Jan 1, 1949

By Je M. Oh

The Bureau of Mines is conducting research to determine the high temperature oxidation resistance of substitute stainless steels (SS) containing two less strategic elements, Al and Si, instead of Cr. Chromium is considered to be a critical and strategic metal. Although the Cr content was reduced to 8 wt pct, the alloys showed better oxidation resistance than did 304 SS containing 18 wt pct Cr. Specifically, the alloys that contained Fe-8Cr-16Ni with combinations of Al and Si showed excellent oxidation resistance even at temperatures up to 1,000° C. In this study, the effects of the alloying elements on oxidation kinetics and morphology of oxides were investigated using a Cahn Rg electrobalance, scanning electron microscopy, an energy-dispersive X-ray analyzer, X-ray diffraction, and an electron microprobe. Aluminum and silicon additions in combinatin were more effective in providing oxidation resistance than either element was alone.

Jan 1, 1986

By Martin Harper

This paper concludes a five year program on research into the use of a portable X ray fluorescence (XRF) analyzer for analyzing lead in air sampling filters from different industrial environments, including mining, manufacturing and recycling. The results from four of these environments have already been reported. The results from two additional metal processes are presented here. At both of these sites, lead was a minor component of the total airborne metals and interferences from other elements were minimal. Nevertheless, only results from the three sites where lead was the most abundant metal were used in the overall calculation of method accuracy. The XRF analyzer was used to interrogate the filters, which were then subjected to acid digestion and analysis by inductively coupled plasma optical emission spectroscopy (ICP OES). The filter samples were collected using different filter holders or "samplers" where the size (diameter), depth and homogeneity of aerosol deposit varied from sampler to sampler. The aerosol collection efficiencies of the samplers were expected to differ, especially for larger particles. The distribution of particles once having entered the sampler was also expected to differ between samplers. Samplers were paired to allow the between sampler variability to be addressed, and, in some cases, internal sampler wall deposits were evaluated and compared to the filter catch. It was found, rather surprisingly, that analysis of the filter deposits (by ICP OES) of all the samplers gave equivalent results. It was also found that deposits on some of the sampler walls, which in some protocols are considered part of the sample, could be significant in comparison to the filter deposit. If it is concluded that wall deposits should be analyzed, then XRF analysis of the filter can only give a minimum estimate of the concentration. Techniques for the statistical analysis of field data were also developed as part of this program and have been reported elsewhere. The results, based on data from the three workplaces where lead was the major element present in the samples, are summarized here. A limit of detection and a limit of quantitation are provided. Analysis of some samples using a second analyzer with a different X ray source technology indicated reasonable agreement for some metals (but this was not evaluated for lead). Provided it is only necessary to analyze the filters, most personal samplers will provide acceptable results when used with portable XRF analysis for lead around applicable limit values.

Jan 1, 2007